/**
* Delete {@code books} from Realm, along with any {@link RBookListItem}s which may exist for
* them, and their cover images if they have them. Optionally delete the real files they were
* imported from as well.
*
* @param realm Instance of Realm to use.
* @param books Books to delete.
* @param deleteRealFiles If true, also delete the books' corresponding files.
*/
public static void deleteBooks(Realm realm, Collection<RBook> books, boolean deleteRealFiles) {
// Null checks.
if (books == null || books.isEmpty()) return;
// If deleteRealFiles is true, check permissions before doing anything.
if (deleteRealFiles
&& !Util.checkForStoragePermAndFireEventIfNeeded(R.id.action_execute_deferred)) {
//noinspection unchecked Defer this action while we ask for permission.
setDeferredAction(params -> deleteBooks(realm, (Collection<RBook>) params[0], true), books);
return;
}
List<String> relPaths = new ArrayList<>(books.size());
// Delete what we created.
realm.executeTransaction(
tRealm -> {
for (RBook book : books) {
// Delete any RBookListItems which may exist for these books.
tRealm
.where(RBookListItem.class)
.contains("book.relPath", book.relPath)
.findAll()
.deleteAllFromRealm();
// Get the relative path of the book, in case we wish to delete the real files too.
String relPath = book.relPath;
relPaths.add(relPath);
// Be sure to delete the cover file, if we have one.
if (book.hasCoverImage) DataUtils.deleteCoverImage(relPath);
// Delete the actual RBook from Realm.
book.deleteFromRealm();
}
});
// If the user wants us to, also try to delete the corresponding files from the device.
if (deleteRealFiles) {
for (String relPath : relPaths) {
File file = Util.getFileFromRelPath(relPath);
if (file != null) // noinspection ResultOfMethodCallIgnored
file.delete();
}
}
}
